kottke.org posts about Robert Coello

Angels pitcher Robert Coello’s unique pitch has knuckleball movement but is thrown with a fastball grip & pitching motion and has a bit more speed on it than a typical knuckleball. His catchers and opposing hitters call it the WTF pitch.

Physicist Alan Nathan, a professor at the University of Illinois who studies baseball and has a particular interest in the knuckleball, hadn’t ever seen a pitch like Coello’s. His preliminary theory on the pitch: His thumb on the underside of the ball exerts backspin, counteracting the tumbling effect his top fingers put on the ball and balancing the torque so perfectly that the pitch has a knuckleball effect with superior speed (around 80 mph).